Hi Carrie,
I don’t currently see any related posts pro instances on your site. I’m guessing that it might be a possible CSS conflict or some sort of override.
Since I can’t see the issue, I can only guess, but I believe that forcing a minimum width on the elements might do the trick.
Try this custom CSS code:
[html].rpp_item {
min-width: 150px !important;
}[/html]
Apply this code to your theme custom CSS field (if it supports it) or use the custom CSS field on the search plugin back-end.